Q. What causes jet lag and how do I get over it?
A. Our bodies operate on a 24-hour circadian rhythm, or internal body clock, which is driven by external environmental cues like sunlight and darkness. The clock guides feelings of alertness in the mornings and sleepiness at night, and it regulates bodily functions such as hunger and temperature. Traveling disrupts that rhythm because there's a desynchronization between the environment and our internal schedule, which leads to jet lag, said Natalie Dautovich, the National Sleep Foundation’s environmental scholar and assistant professor of psychology at the University of Alabama.
If you know a trip is coming up, Dautovich recommends planning ahead by adjusting your daily schedule — for example, waking up and going to sleep earlier, depending on where you’re traveling — to mitigate the time changes.
Natural light is the most powerful environmental cue in regulating body clocks, so being exposed to outdoor light, even on a cloudy day, will help reset body clocks faster, once you arrive at your destination and again when you return.
Additionally, many people experience discomfort sleeping because they’re in an unfamiliar environment, Dautovich said, a phenomenon known as “first-night effect.” Bringing familiar objects from home and setting a night-time environment, either by minimizing light by drawing the curtains, wearing a sleep mask, or setting a cool and quiet environment can help troubled sleepers.
“You’re going to feel tired and sluggish so our natural desire is to give into the desire to sleep and nap,” Dautovich said. “But we need to minimize naps and keep to a regular sleep-wake schedule.”